This paper,by using imaginary plane method,studies the change law of the coefficient for angle of radiation in raw gas exchanger for ascension pipe.The result shows that in heat exchanger of the ascension pipe,the coefficient for angle of radiation of the oven chamber hot coke opposite to the side of heat exchanger goes down with increasing height of the ascension pipe;i.e.with fixed height of the ascension pipe and increasing length to diameter ratio,the coefficient for angle of radiation of the oven chamber hot coke opposite to the side of heat exchanger decreases; with fixed diameter of the ascension pipe,there would be not obvious change in this coefficient;when the length to diameter ratio is fixed,this coefficient will increase with increasing height and diameter of the ascension pipe.When the gap increases between the hot coke surface and the lower flange of the ascension pipe,this coefficient will decrease accordingly.

Ascension pipe, Imaginary plane method, Angle coefficient, Length to diameter ratio